Mobile adjustable scaffold



July 30, 1968 w. H. GLOVER MOBILE ADJUSTABLE SCAFFOLD 4 Sheets-Sheet 1 Filed Feb. 15, 1967 INVENTOR WILLIAM H. GLOVER BY 7PM ATTORNEYS July 30, 1968 w. H. GLOVER 3,394,777

MOBILE ADJUSTABLE SCAFFOLD Filed Feb. 15, 1967 4 Sheets-Sheet 2 INVENTOR 1 WILLIAM H. GLOVER J QW WM AT TORNE YS July 30, 1968 Filed Feb. 15,

4 Sheets-Sheet 3 INVEN TOR WILLIAM H. GLOVER AT TORNEYS July 30, 1968 w. H. GLOVER MOBILE ADJUSTABLE SCAFFOLD 4 Sheets-Sheet 4 Filed Feb. 15, 1967 INVENIOR WILLIAM H. GLOVER BY 241M,

ATTORNEYS United States Patent 3,394,777 MOBILE ADJUSTABLE SCAFFOLD William H. Glover, P.O. Box 102, Kingston, Wis. 53939 Filed Feb. 15, 1967, Ser. No. 616,351 Claims. (Cl. 182-131) ABSTRACT OF THE DISCLOSURE A wheel supported scaffold having lower upright platform support posts which may be pivoted fore and aft and telescoping inner brace members for maintaining the platform support posts in substantially upright position; upper platform support posts attached in removable relation to the upper ends of the lower support posts, telescoping base members and outer brace members for maintaining the upper platform support posts in upright position for supporting workers at higher elevations. The lower platform support posts are removable and the upper sections of the inner brace members are also removable from the lower sections thereof whereby the lower sections may be pivoted down into a substantially horizontal position over the wheels for highway travel. The platform plank support members at both sides are independently vertically adjustable for maintaining the working platforms in substantially horizontal position.

Background of the invention (1) Field of the invention.This invention pertains generally to the field of scaffolds and more particularly to mobile adjustable scaifolds.

(2) Description of the prior art-Typically, scaffolding equipment of sufficient size to support a number of construction workers or the like has not been easily movable about on the job site and has been even more cumbersome to transport on the highway.

Mobile scaffolds of known construction have not generally been designed with adequate means to keep the working platforms level when the mobile unit must be used on sloping and uneven terrain such as usually found at construction sites.

In recent years mobile hydraulic powered, extendable sky-buckets for moving a worker to an elevated working position have come into use for many jobs, however, they are expensive and are not well suited for construction work since they generally are not of sufficient size and stability to support a number of workers nor do they permit workers such as bricklayers, steel erectors, and the like to move laterally as plank-type scaffolds do.

Summary of the invention Because of the obvious need for improved scaffolding for the construction industry and other related industries, I have invented a sturdy, yet inexpensive mobile plank-type scaffold unit which is both easily movable about at the job site and which can be easily collapsed into a compact unit for highway travel.

Furthermore, the platform supporting members at each side of my scaffold unit can be independently vertically adjusted and the platform supporting posits are pivotably mounted at their lower ends allowing them to be swung fore and aft, whereby the working platforms can always be leveled regardless of the slope of the ground on which the wheels of the chassis are resting.

My mobile scaffold unit will hold a number of workers at any desired level up to the top of the unit on planktype platforms for allowing workers such as steel erectors, bricklayers, and the like lateral movement along the platforms. A number of platforms are provided for simultaneously supporting workers at different levels. The scaftold is also extendable in that it has upper platform support posts and telescoping base and brace members for supporting workers at higher elevations as the work progresses upwardly.

Brief description of the drawings FIGURE 1 is a perspective view of a mobile adjustable scaffold exemplifying my invention.

FIGURE 2 is a rear elevation view of the scaffold of FIGURE 1.

FIGURE 3 is a side elevation view of the scaffold of FIGURE 1.

FIGURE 4 is a schematic side view illustrating the use of my scaffold on sloping terrain. 1

FIGURE 5 is a schematic front view illustrating the use of my scaffold on sloping terrain.

Description of the prefered embodiment Referring now more particularly to the drawings wherein like numerals refer to like parts throughout the several views, my mobile adjustable scaffold is generally shown at 30 in FIGURES 13.

Scaffold 30 comprises a trailer chassis 31 having axle members 32 and conventional inflated rubber tires 33 suitable for highway travel. The scaffold has right and left primary base members 34 fixedly mounted in substantially horizontal position by steel base plates 35 on axle members 32. It will be noted that the front of the scaffold (right side in FIGURE 3) faces what would ordinarily be considered the side of the trailer chassis.

The primary base members 34 are tubular and are preferably comprised of S-foot lengths of 2-inch diameter steel pipe. As best seen in the side elevation view of FIGURE 3, the front ends of primary base members 34 are located inwardly of the wheels 'at one side of the chassis while the rear ends thereof extend over the wheels at the other side of the chassis to provide proper balance for the scaffold. A pair of attaching sleeves 36 comprising short lengths of Z-inch steel pipe are pivotally mounted at the front ends of primary base members 34 by brackets 37 for pivotal movement forwardly and realwardly; i.e., right and left, respectively, in FIGURE 3.

A pair of upright lower platform support posts 38 comprising l /z-inch steel pipe are removably secured in sleeves 36 by set screws 39. The lower platform support posts 38 shown in the drawings for exemplification are 20 feet long.

A pair of inner, extensible brace members 40 are provided for maintaining lower posts 38 in substantially upright position. The brace members 40 are comprised of lower sections 40a which receive upper sections 40b in telescoping relation. The lower sections 40a are pivotally attached at their lower ends to the rear ends of primary base members 34 by connecting lugs 41 which are welded to the primary base members 34. The upper sections 40b are pivotally attached to coupling sleeves 42 mounted on the upper ends of lower posts 38. The lower sections 40a of inner braces 40 are preferably made of 5-foot lengths of l fit-inch steel pipe and the upper sections 40b are made of 17 /z-foot lengths of 1-inch steel pipe. The coupling sleeves 42 are made of 2-inch steel pipe approximately 8 inches long.

The lower brace sections 40a are kept relatively short so that when the scaffold is to be collapsed for highway travel, the upper brace sections 4% may be removed from the lower sections by releasing set screws 43 thus enabling the lower sections 40a to be pivoted into a substantially horizontal position shown in broken lines in FIGURE 3.

The upper ends of lower platform support posts 38 are supported by a cross-brace 44 which is securely attached to coupling sleeves 42 by set screws 45 which are tightened down onto attaching projections 46 on the coupling sleeves 42. The cross-brace 44 is formed of lMt-inch steel pipe 10 feet long. Diagonally extending cross-braces 47 are bolted at their lower ends to sleeves 36 and at their upper ends to coupling sleeves 42 to provide lateral rigidity to the scaffold.

Vertically adjustable platform support members 48 are mounted on the lower platform support posts 38. Each of the platform support members comprises a sleeve 49 made of 2-inch steel pipe approximately 2-feet long. Each sleeve 49 has a substantially horizontal platform support pipe 50 extending forwardly therefrom for supporting platform planks 51. Bracing pipes 52 are provided for horizontal platform support pipes 50. The platform support pipes 50 have plank stop plates 53 welded on the ends thereof to prevent the planking from falling off the ends thereof. The platform panks 51 have wood cleats 54 attached to the underside thereof immediately adjacent each side of the platform support pipes 50 to prevent the planks from sliding laterally.

The platform support sleeves 49 are each independently vertically slideable on the lower support posts 38 and can be secured at any desired elevation by set screws 55 for keeping the platforms 51 level.

As best shown in FIGURE 3, when the wheels 33 of the chassis 31 are resting on substantially horizontal supporting terrain, the primary base members 34, lower posts 38 and brace members 40 form a right-triangle wherein the lower posts 38 are substantially vertical so that the working platforms 51 are maintained substantially horizontal.

As shown schematically in FIGURE 4, should the wheels of the chassis 31 be resting on terrain which slopes away from the building being constructed, the brace members 40 are merely extended until the lower platform support posts 38 are brought into vertical alignment whereby the working platforms 51 thereon are maintained in a horizontal position. On the other hand, should the terrain slope toward the building, the brace members 40 would merely be telescoped together until the lower platform support posts 38 are again brought into a vertical alignment whereby the angle between the pirmary base members 34 and the lower platform support posts 38 would be something less than a right angle.

As shown schematically in FIGURE 5, if the wheels of the chassis are resting on longitudinally sloping terrain, the working platforms 51 can be maintained in horizontal alignment by merely adjusting the platform support sleeves 49 as shown. Thus, it is readily apparent that the working platforms can always be maintained in a horizontal position regardless of the slope of the terrain on which the mobile scaffold is used.

My scaffold is designed with an extendable portion for reaching working positions which cannot be reached from the working platforms 51 supported on the lower platform support posts 38. The primary base members 34 are tubular for receiving secondary base members 56 in telescoping relation. As best seen in the side elevation view of FIGURE 3, in the extended position shown, the rear ends of the secondary base members 56 extend well beyond the side of the chassis to provide proper balance for the scaffold unit. The secondary base members are made of l /z-inch pipe approximately S-feet long. The primary base members 34 are provided with set screws 57 for fastening the secondary base members 56 in the extended position shown in FIGURE 3 during use, and for fastening them in the telescoped position shown in broken lines in FIGURE 3 for highway travel.

Upper platform support posts 58 in the form of 10-foot lengths of l /z-inch steel pipe are mounted in coupling sleeves 42 and are releaseably secured therein by set screws 59. Outer, extensible brace members 60 are provided for bracing the upper posts 58 in upright position. The outer brace members are comprised of lower sections 60a comprising a 16-foot length of Z-inch pipe pivotally attached to the rear ends of secondary brace members 56 by connecting lugs 61. The upper sections 60b comprise 17 /2-foot lengths of l Az-inch steel pipe telescoped into the lower sections 60a and pivotably attached at their upper ends to sleeves 62 secured to the upper ends of upper platform support posts 58.

The 10-foot upper posts 58 may carry two platforms 63 similar to the platforms 51 carried on the lower posts 38.

My mobile scaffold may be moved about a construction site in its upright extended position, however, it is collapsible to facilitate traveling on the highway from site to site. To collapse the extended scaffold unit, the lower ends of outer brace members 60 are detached from connecting lugs 61 and the upper platform support posts 58 are removed from the coupling sleeves 42 at the upper ends of the lower posts 38 by loosening set screws 59. The secondary base members 56 may then be telescoped into the primary base members 34 to the position shown in broken lines in FIGURE 3 by loosening set screws 57 and secured therein for highway travel by retightening these screws.

The lower platform support posts 38 may then be removed from the sleeves 36 by loosening set screws 39 and the upper sections 40b of inner brace members 40 are removed from the lower sections 40a thereof by releasing set screws 43. The lower sections 40a of inner brace members 40 may then be pivoted down into the position shown in broken lines in FIGURE 3 for traveling.

All of the scaffold parts may be carried on the trailer chassis to the next job site by placing the platform planks and pipe members longitudinally across the primary base members 34 or across the axle members 32 of the chassis for highway travel.

It is understood that my invention is not confined to the particular construction and arrangement of parts herein illustrated and described, but embraces all such modified forms thereof as come within the scope of the following claims.

I claim:

1. Mobile adjustable scaffold comprising:

(A) a wheel supported trailer chassis,

(B) a pair of base members fixedly mounted on said chassis, said base members having front and rear ends,

(C) a pair of upright posts hingedly mounted at their lower ends to the front ends of said base members for swinging forwardly and rearwardly,

(D) a pair of extensible brace members hingedly connected to the rear ends of said base members and to the upper ends of said posts for supporting said posts in substantially upright position,

(E) cross-bracing for said posts, and

(F) independently vertically adjustable platform support means on said posts.

2. The scaffold as specified in claim 1 wherein the lower ends of said posts are removably supported in sleeve means hingedly connected at the front ends of said base members whereby said posts may be removed from said sleeve means for traveling.

3. The scaffold as specified in claim 1 wherein said extensible brace members have:

(i) lower sections hingedly connected to the rear ends of said base members,

(ii) upper sections hingedly connected to the upper ends of said posts and telescopingly received in said lower sections whereby said upper sections can be removed from said lower sections for traveling,

(iii) means for releasably locking said telescoping upper and lower sections together,

(iiii) said lower sections being of such a length that they may be pivoted down over the trailer chassis into a substantially horizontal travel position.

4. The scaffold as specified in claim 1 wherein said platform support means comprises:

(i) a tubular sleeve slideably mounted on each of said posts, said sleeves being movably independently of each other,

(ii) means for releasably securing each of said tubular sleeves at any desired elevation on said posts, and (iii) a substantially horizontal portion extending from each of said sleeves for supporting platform planks thereacross.

5. The scaflold as specified in claim 2 wherein said sleeve means have set screws therein for frictionally locking said sleeves on said posts.

6. Mobile adjustable scaifold comprising:

(A) a wheel supported trailer chassis,

(B) a pair of substantially horizontal primary base members fixedly mounted on said chassis, said primary base members being tubular and having front and rear ends,

(C) a pair of upright lower posts hingedly mounted at their lower ends to the front ends of said primary base members for swinging forwardly and rearwardly,

(D) a pair of inner extensible brace members hingedly connected to the rear ends of said primary base \members and to the upper ends of said lower posts for supporting said lower posts in substantially upright position,

(E) coupling means at the upper ends of said lower posts,

(F) a pair of upright upper posts having their lower ends removably secured in said coupling means at the upper ends of said posts,

(G) a pair of secondary base members telescopingly mounted in the rear ends of said primary base members, said secondary base members being adapted to have their rear ends extend beyond the trailer chassis,

(H) a pair of outer extensible brace members hingedly connected to the rear ends of said secondary base members and to the upper ends of said upper posts for supporting said upper posts in substantially upright position,

(I) cross-bracing for said posts, and

(J) independently vertically adjustable platform support members on said upper and lower posts.

7. The scatfold as specified in claim 6 wherein the inner extensible brace members have:

(i) lower sections hingedly connected to the rear ends of said primary base members,

(ii) upper sections hingedly connected to the upper ends of said lower posts and telescopingly received in said lower sections whereby said upper sections can be removed from said lower sections for travel- (iii) means for releasably locking said telescoping upper and lower sections together,

(iiii) said lower sections being of such a length that they may be pivoted down over the trailer chasis into a substantially horizontal travel position.

8. The scaffold as specified in claim 6 wherein the lower ends of said right and left lower posts are removably supported in sleeve means hingedly connected at the front ends of said primary base members whereby said lower posts may be removed from said sleeve means for travelmg.

9. The scafiold as specified in claim 6 wherein said platform support means comprises:

(i) a tubular sleeve slideably mounted on each of said upper and lower posts, said sleeves being movable independently of each other,

(ii) means for releasably securing each of said tubular sleeves at any desired elevation on said posts, and

(iii) a substantially horizontal portion extending from each of said sleeves for supporting latfonm planks thereacross.

10. The scaffold as specified in claim 6 wherein said sleeve securing means comprise set screws for frictionally locking said sleeves on said posts.

References Cited UNITED STATES PATENTS 60,947 l/1867 Simpson 182-130 283,650 8/1883 O-rmsby 182145 315,902 4/1885 Brown 182132 1,339,661 5/1920 Milton 182132 3,156,317 11/1964 Lundeen 182-17 3,282,376 11/1966 Merriman 182-17 REINALDO P. MACHADO, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE" OF CORRECTION Patent No. 3,394,777 July 30, 1968 William H. Glover It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shovm below:

Column 1, line 61, "posits" should read posts Column 3, line 17, "panks" should read planks line 42, "pirmary" should read primary Column 5, line 31, after "said" insert lower Signed and sealed this 16th day of December 1969.

( A Attest:

Edward M. Fletcher, Jr. WILLIAM E. SCHUYLER, JR.

Commissioner of Patents Attesting Officer 

